Monocyte-macrophage lineage of giant cell tumor of bone. Establishment of a multinucleated cell line.

METHOD: A new neoplastic cell line, UISO-GCT-1, was established from a giant cell tumor of the right tibia in an 18-year-old man. Immunohistochemical, cytogenetic, ultrastructural, and growth studies were performed.
RESULTS: Multinucleated giant cells (> 4-6 nuclei/cell) persisted in a culture relatively late in passage (passage 17), which is unique in cell lines of giant cell tumor of bone. Mononuclear and multinucleated cells in monolayer culture expressed vimentin and tartrate-resistant acid phosphatase and reacted with monoclonal antibodies to CD13 and CD68, suggesting a monocytic-macrophage origin of these cells. Mononuclear and multinuclear cells also selectively expressed high molecular weight cell membrane antigens specifically associated with soft tissue sarcomas and osteosarcomas. Karyotypically, UISO-GCT-1 cells were hypodiploid, hypotetraploid, and multiploid, with more than 200 chromosomes per mitosis present in some cells. Other chromosomal aberrations observed included ring chromosomes, double minutes, translocations, multiple fragments, and multiradials.
CONCLUSION: Collectively, observations of this study suggest that karyotypically abnormal giant cell tumors of bone arise from a monocyte-macrophage lineage and subsequently express an antigenic profile similar to malignant mesenchymal tumors.